Beyond vegetation-based habitat restoration for a threatened giant Spirostreptid millipede

Vegetation-based restoration efforts often fail to provide suitable habitat for many invertebrates. Restoring habitat for target invertebrates requires an understanding of their resource and condition requirements. The Seychelles giant millipede (SGM), Sechelleptus seychellarum, is a functionally important millipede which is Red Listed as ‘Vulnerable’. Here, we studied the habitat requirements of this macro-detritivore in relation to the ongoing forest restoration programme on Cousine Island, Seychelles. SGM spatial density did not significantly correlate with edaphic and litter properties, but did positively correlate with the toposcape (i.e. elevation and granitic rock cover). Granite rock crevices in forest covered areas were important diurnal refuges for the SGM, as microclimate conditions in non-forest covered rock refuges were unsuitable. SGM physical condition was significantly lower in non-shaded crevices compared to those shaded by forest. Low granite rock cover in the restored forest limited the SGM colonisation of this area in large numbers, despite canopy cover in the restored forest being comparable with that in the reference natural forest. As most restoration practices are primarily vegetation-based, this study demonstrates that such an approach can be inadequate for restoring habitat for target invertebrates, as many species habitat requirements extend beyond that of vegetation. For the SGM, selecting restoration sites that already have abundant rock cover would be the most practical way to increase SGM habitat through forest restoration practices. Taking into consideration the habitat requirements of target invertebrates can help in setting or redirecting restoration goals and thus enhance the conservation value of such practices.     

Population dynamics of a threatened giant millipede: implications for restoration

The population dynamics of threatened invertebrates have important implications for their conservation and restoration. The Seychelles giant millipede (SGM), Sechelleptus seychellarum, is a threatened and functionally important macro‐detritivore endemic to the Seychelles granitic islands. Here, we studied the population dynamics of the SGM from 1998 to 2009 on Cousine Island, Seychelles, to make practical restoration recommendations. Large fluctuations in millipede densities were found between 1998 and 2009. In 2002, 2003, 2005, and 2007 millipede densities were low, while densities were high in 1998 and 2009. Although the SGM is active all year round, millipede surface activity was positively correlated with rainfall, with millipede density high during the wet NW monsoon period (i.e., October to April) and low during the SE trade wind period (i.e., May to September). Female:male:juvenile ratios were ～3:1:1. The implications of these results for restoration are that translocations should preferably be done in years of high millipede densities and during the wet season. Furthermore, chemical control of the invasive ant Pheidole megacephala, which is currently being carried out on Cousine Island and in future could be conducted on other Seychelles islands, should preferably be done during the low rainfall months, as the SGM readily consumes the hydramethylnon‐based bait.     

土壤细菌呼吸对西双版纳热带森林恢复的响应

揭示不同恢复阶段热带森林土壤细菌呼吸季节变化及其主控因素,对于探明土壤细菌呼吸对热带森林恢复的响应机制具有重要的科学意义。以西双版纳不同恢复阶段热带森林(白背桐群落、崖豆藤群落和高檐蒲桃群落)为研究对象,运用真菌呼吸抑制法及高通量宏基因组测序技术分别测定土壤细菌呼吸速率和细菌多样性,并采用回归分析及结构方程模型揭示热带森林恢复过程中土壤细菌多样性、pH、土壤碳氮组分变化对土壤细菌呼吸速率的影响特征。结果表明：1)不同恢复阶段热带森林土壤细菌呼吸速率表现为：高檐蒲桃群落((1.51±0.62)CO₂ mg g^-1 h^-1)显著高于崖豆藤群落((1.16±0.56)CO₂ mg g^-1 h^-1)和白背桐群落((0.82±0.60)CO₂ mg g^-1 h^-1)(P<0.05)。2)不同恢复阶段土壤细菌呼吸速率呈显著的单峰型季节变化(P<0.05),最大值均出现在9月：高檐蒲桃群落((...     

Exploiting fruits of a threatened palm to trigger restoration of Brazil's Atlantic Forest

Recent global commitments to forest and landscape restoration in the tropics call for new management approaches that benefit both biodiversity and livelihoods of forest‐dependent people. The sustainable use of wild forest products is a promising pathway, but requires clarity about harvested species' demography and harvesters' rights. Here, we explored how the exploitation of fruits of the threatened palm Euterpe edulis, a key fruit source for wildlife in Brazil's globally important Atlantic Forest biodiversity hotspot, could trigger local community involvement in restoration. This palm has both non‐destructive (fruit) and destructive (palm heart) culinary uses, each with unique biological and resource‐use conditions. We quantified all demographic stages of this species in multiple agroforests, secondary forests, and protected areas to parameterize demographic projections of palm populations, harvest profitability, and fruit provisioning to wildlife under different management scenarios. Field observations showed a clear depression of adult palm populations in protected areas, likely due to palm heart poaching, and of intermediate size classes in agroforests, probably from weeding by farmers. Field data and demographic models reveal that in this region, agroforests and secondary forests can successfully conserve this species while providing lasting profits for farmers under most scenarios. These findings demonstrate a clear case where local stakeholders both contribute to and benefit from restoration through harvest of wild products and also highlight a potential source of income from regenerating tropical forests.     

Species diversity in restoration plantings: Important factors for increasing the diversity of threatened tree species in the restoration of the Araucaria forest ecosystem

The Araucaria forest ecosystem in southern Brazil is highly threatened: less than one percent of the original forest remains, and what is left is a fragmented agro-mosaic of mostly early-to-late secondary forest patches among high-yield agriculture and timber monocultures. Forest restoration initiatives in this region aim to restore degraded areas, however the limited number of species used in restoration projects represents a missed opportunity for species-rich plantings. High diversity plantings represent a larger number of functional groups and provide a targeted conservation strategy for the high number of threatened species within this ecosystem. This study interviewed nurseries(Ns) and restoration practitioners(RPs) in Parana and Santa Catarina states to identify what species are being cultivated and planted, and what factors are driving the species selection process. An average of 20 species were reportedly used in restoration plantings, most of which are common, widespread species. Baseline data confirms that Ns and RPs have disproportionately low occurrences of threatened species in their inventories and plantings, supporting findings from previous research. Questionnaire responses reveal that opportunities for seed acquisition are an extremely important factor in order for nurseries to increase their diversity of cultivated species. Results also suggest that facilitating speciesrich plantings for restoration practitioners would only be feasible if it did not increase the time required to complete planting projects, as it would minimize their ability to keep costs low. This study proposes solutions for increasing the number of species used in restoration practicedsuch as developing a comprehensive species list, fostering knowledge-sharing between actors, creating seed sharing programs, and increasing coordination of planting projects. Long-term strategies involve complimenting traditional ex situ approaches with emerging inter-situ and quasi in situ conservation strategies which simultaneously provide long-term preservation of genetic diversity and increase seed production of target species.     

Response of plant functional traits during the restoration of calcareous grasslands from forest stands

In this survey, we studied the response of plant functional traits to calcareous grassland restoration in the Calestienne region, Southern Belgium (restoration protocol: forest clear-cutting followed by grazing at all sites). We considered traits related to dispersal, establishment, and persistence that integrate the main challenges of plants to re-establish and survive in restored areas. Functional traits were compiled from databases and compared among (i) pre-restoration and young restoration forests; (ii) restoration areas of different ages; and (iii) old restorations and reference grasslands. The following questions were addressed: (i) What is the early response (2–4 years) in terms of plant functional trait following one restorative clear-cut event? (ii) What plants functional trait responses occur from restorative management (i.e., sheep and goat grazing)? (iii) Which differences still persist between the oldest restored parcels (10–15 years), and the historical reference grasslands? Forest clear-cuts induced several changes among functional traits, including decreased mean seed mass and certain vegetative traits (i.e., decreased phanerophytes, branching species; and increased short lifespan species i.e., annuals and biennials). During restorative management, clonal, epizoochorous and autumn germinating species were favored. Despite numerous other changes during this phase, many differences remained compared to reference grasslands. In particular, geophytes, mycorrhizal and evergreen species abundance were not approaching reference grassland values. The observed pattern helped to draw inferences on the possible mechanisms operating under vegetation recovery following restorative forest clear-cut and subsequent management were identified and described in this study. Results indicated grazing was an important factor, which increased epizoochorous species, and autumn germinating taxa that filled niches in vegetation opened by summer grazing animals. Finally, differences between old restoration and reference grasslands emphasized that management should focus on reduction in soil fertility, and geophyte rhizomatous grasses. Long-term monitoring is vital to assess if management plans are effective in the complete restoration of species functional trait assemblages.     

Leaf litter arthropod responses to tropical forest restoration

Soil and litter arthropods represent a large proportion of tropical biodiversity and perform important ecosystem functions, but little is known about the efficacy of different tropical forest restoration strategies in facilitating their recovery in degraded habitats. We sampled arthropods in four 7‐ to 8‐year‐old restoration treatments and in nearby reference forests. Sampling was conducted during the wet and dry seasons using extractions from litter and pitfall samples. Restoration treatments were replicated in 50 × 50‐m plots in four former pasture sites in southern Costa Rica: plantation – trees planted throughout the plot; applied nucleation/islands – trees planted in patches of different sizes; and natural regeneration – no tree planting. Arthropod abundance, measures of richness and diversity, and a number of functional groups were greater in the island treatment than in natural regeneration or plantation treatments and, in many cases, were similar to reference forest. Litter and pitfall morphospecies and functional group composition in all three restoration treatments were significantly different than reference sites, but island and plantation treatments showed more recovery than natural regeneration. Abundance and functional group diversity showed a much greater degree of recovery than community composition. Synthesis and applications: The less resource‐intensive restoration strategy of planting tree islands was more effective than tree plantations in restoring arthropod abundance, richness, and functional diversity. None of the restoration strategies, however, resulted in similar community composition as reference forest after 8 years of recovery, highlighting the slow rate of recovery of arthropod communities after disturbance, and underscoring the importance of conservation of remnant forests in fragmented landscapes.     

Process-centred restoration in a fire-adapted ponderosa pine forest

Accurate and ecologically meaningful characterisation of reference conditions is a fundamental premise of restoration ecology. Restoration practice and research commonly define reference conditions in terms of compositional and structural elements. We propose a “process-centred” framework that places central emphasis on ecological functions and ecosystem processes. A wide variety of processes is central to the functioning and dynamics of ecological systems, and can be placed at the foundation of restoration research and practice. A process-centred approach allows the definition of “reference dynamics”, where spatial and temporal variability and underlying mechanisms of change are primary. We illustrate this approach using a 303-yr reconstruction of the natural surface fire regime to guide restoration of a Pinus ponderosa forest in the Jemez Mountains of southwestern North America. Fire occurrence varied over space and time during the period of record, with ecologically significant variation in fire intervals (yr fire⁻¹) governed by process–structure interactions. We defined a variety of reference variables for reintroduction of fire as the keystone ecological process, along with related structural variation. A process-centered approach and the reference dynamics paradigm can replace a more static concept of reference conditions in defining restoration baselines and provide an improved standard of comparison for restoration ecology.     

The potential of soil seed banks of a eucalypt wetland forest to aid restoration

Soil seed banks can play an important role in the regeneration of wetland vegetation. However, their potential role in the restoration of degraded wetland forests is less certain. I surveyed the soil seed bank and extant floras of four sites across a eucalypt wetland forest of variable vegetation condition. At each site, the extant vegetation was surveyed within two 5 × 5 m² quadrats, each from which five composite soil seed bank samples were collected. Across the four sites, 57 (including 18 exotic) species were identified in the extant vegetation, while from the seed bank samples 6379 seedlings emerged from 80 taxa, 33 of which were exotic species. The soil seed bank was dominated by native and exotic monocots, and contained very few seeds of wetland tree or shrub species. Overall, the similarity between the extant and seed bank floras was very low (~24 %). Soil seed banks are likely to be of limited use in the restoration of degraded wetland forests, because the dominant species in such systems—woody and clonal plants—are typically absent from the soil seed bank. Wetland soil seed banks may contribute to the maintenance and diversity of understorey vegetation, however, they may also act as a source of exotic plant invasions, particularly when a wetland is degraded.     

Preliminary evidence for a two‐for‐one deal: Wetland restoration for a threatened frog may benefit a threatened bat

Habitat restoration is an integral feature of wildlife conservation. However, funding and opportunities for habitat restoration are limited, and therefore, it is useful for targeted restoration to provide positive outcomes for non‐target species. Here, we investigate the possibility of habitat creation and management benefitting two threatened wetland specialists: the Green and Golden Bell Frog (Litoria aurea) and the Large‐footed Myotis (Myotis macropus). This study involved two components: (i) assessing co‐occurrence patterns of these species in a wetland complex created for the Green and Golden Bell Frog (n = 9) using counts, and (ii) comparing foraging activity of Large‐footed Myotis in wetlands with low and high aquatic vegetation (n = 6 and 7, respectively) using echolocation metres. Since Large‐footed Myotis possesses a unique foraging behaviour of trawling for aquatic prey, we hypothesised that foraging activity of this species would be higher in wetlands with low aquatic vegetation coverage. Additionally, we provide observations of its potential prey items. We identified one created wetland where both species were found in relatively high numbers, and this wetland had a permanent hydrology, was free of the introduced fish Gambusia (Gambusia holbrooki) and had low aquatic vegetation coverage. We also found that Myotis feeding activity was significantly higher in low aquatic vegetation coverage wetlands (x? = 65.72 ± 27.56 SE) compared to high (x? = 0.33 ± 0.33 SE, P = 0.0000). Although this is a preliminary study, it seems likely that Green and Golden Bell Frog and Large‐footed Myotis would gain mutual benefit from wetlands that are constructed to be permanent, that are Gambusia free, low in aquatic vegetation coverage, and are located in close to suitable roosting habitat for Large‐footed Myotis. We encourage adaptive aquatic vegetation removal for Green and Golden Bell frog as this may have benefits for Large‐footed Myotis. The evidence suggests that the former may be a suitable umbrella species for the latter.     

热带森林植被生态恢复研究进展

热带森林是地球上生物多样性最高和生态功能最为强大的植被类型之一,在维护全球生态平衡中起着至关重要的作用,同时也为人类社会提供着多种多样的物质资源和生态系统服务。然而热带森林是目前生物多样性消失最快和生态功能退化最为严重的生态系统之一,如何有效地保护现存的热带森林不再进一步退化,以及如何使已经退化的生态系统尽快得到恢复是生态学工作者面临的重要议题。不同方式、规模和强度的干扰对热带林的破坏程度及其以后的恢复过程产生的影响不同。除少数大型自然干扰事件外,采伐、刀耕火种、农业开发用地等人为干扰是造成当前热带森林植被大面积退化的主要原因。多种干扰交互作用、杂草与外来物种入侵、退化植被和土壤状况、残存植被组分及土壤种子库、退化植被周围的景观格局以及全球气候变化等因素都能够影响热带森林植被恢复的速度和方向。基于功能群的研究思想将可能为物种丰富的热带森林植被恢复的研究提供一个全新途径。     

Soil millipede diversity in tropical forest patches and its relation to landscape structure in northeastern Puerto Rico

Uncontrolled urban development is threatening the survival of many terrestrial species worldwide, especially those with limited dispersal capabilities. Soil invertebrates account for a high proportion of the global biodiversity but there are few studies on how soil biodiversity varies with different parameters of landscape structure, especially in fragmented tropical habitats. Millipedes are among the most abundant detritivore invertebrates in the soil-litter macrofauna. We examined the relationships between soil millipede diversity and landscape structure in 12 forest patches of approximately 30 years of age, in northeastern Puerto Rico. Spatial characteristics of the landscape were determined from aerial color photographs and were digitized into a GIS package for analysis. Millipede species diversity and composition in these forest patches showed correlations with their surroundings (e.g. amount of forest in the matrix) and with the presence of vegetation corridors that connected to other forest patches, rather than forest patch attributes such as patch area and shape. Millipede species richness correlated negatively with the degree of isolation of forest patch (within 600 m radius), while species evenness correlated positively to the amount of forest within a 50 m buffer. Millipede species composition was related with the presence of vegetation corridors and the distance to the Luquillo Experimental Forest reserve. These findings show that a low degree of patch isolation, forested buffers, and presence of vegetation corridors need to be considered for the conservation and management of forest patches surrounded by urban developments, especially to protect terrestrial invertebrate species that require forested habitats for their dispersal.     

稀土尾矿土壤细菌群落结构对植被修复的响应

选用赣州-安远稀土弃废尾矿及其不同植被修复的堆浸田为研究对象,调查废弃尾矿及6种不同植被修复方案下土壤理化性质的变化,并利用变性凝胶梯度电泳(DGGE)技术,分析土壤微生物群落结构对植被修复的响应。结果表明:与未修复尾矿土壤相比,经不同植被修复后的土壤理化性质均得到明显改良,其中土壤含水量、有机质含量均比未修复尾矿土壤增加2—3倍。微生物群落结构分析表明,植被修复后土壤微生物群落与废弃尾矿土壤微生物群落亲缘度仅为0.21,表明植被修复后,土壤微生物群落结构发生了明显变化,且微生物多样性、均匀度、丰富度与未修复尾矿土壤相比均有了明显的提高。而在不同植被修复方案中,以湿地松和山胡椒为优势群落的两种植被修复方案对土壤改良效果最为明显,这两种修复方案不仅能显著改善土壤的固水性、有机质含量,并且对微生物群落的改善作用也最为显著。典范对应分析表明,废弃尾矿土壤微生物群落结构受土壤p H影响最为显著,而植被修复后土壤微生物群落的环境影响因子则转变为含水量、有机质、有机碳及总磷含量。进一步揭示了微生物在植被修复过程中所起到的重要作用,并为矿山生态重建过程中的土壤改良工作提供了丰富的理论依据。     

Applying climate change refugia to forest management and old-growth restoration

Recent studies highlight the potential of climate change refugia (CCR) to support the persistence of biodiversity in regions that may otherwise become unsuitable with climate change. However, a key challenge in using CCR for climate resilient management lies in how CCR may intersect with existing forest management strategies, and subsequently influence how landscapes buffer species from negative impacts of warming climate. We address this challenge in temperate coastal forests of the Pacific Northwestern United States, where declines in the extent of late-successional forests have prompted efforts to restore old-growth forest structure. One common approach for doing so involves selectively thinning forest stands to enhance structural complexity. However, dense canopy is a key forest feature moderating understory microclimate and potentially buffering organisms from climate change impacts, raising the possibility that approaches for managing forests for old-growth structure may reduce the extent and number of CCR. We used remotely sensed vegetation indices to identify CCR in an experimental forest with control and thinned (restoration) treatments, and explored the influence of biophysical variables on buffering capacity. We found that remotely sensed vegetation indices commonly used to identify CCR were associated with understory temperature and plant community composition, and thus captured aspects of landscape buffering that might instill climate resilience and be of interest to management. We then examined the interaction between current restoration strategies and CCR, and found that selective thinning for promoting old-growth structure had only very minor, if any, effects on climatic buffering. In all, our study demonstrates that forest management approaches aimed at restoring old-growth structure through targeted thinning do not greatly decrease buffering capacity, despite a known link between dense canopy and CCR. More broadly, this study illustrates the value of using remote sensing approaches to identify CCR, facilitating the integration of climate change adaptation with other forest management approaches.     

Rapid colonization of a Hawaiian restoration forest by a diverse avian community

Deforestation of tropical forests has led to widespread loss and extirpation of forest bird species around the world, including the Hawaiian Islands which have experienced a dramatic loss of forests over the last 200–800 years. Given the important role birds play in forest ecosystem functions via seed dispersal and pollination, a bird community's response to forest restoration is an important measure of the success of such conservation actions. We evaluated the bird response to reforestation at an important bird sanctuary, Hakalau Forest National Wildlife Refuge, Hawai′i Island, using 26 years of bird count data. We show that most species from within the diverse avian community increased significantly, but species colonized the restoration forest at different rates. Distance from intact forest and time since restoration were both important predictors of colonization rate, interacting such that for most species it took more time to colonize areas farther from the intact forest. In addition, both forest cover and understory diversity helped to explain bird densities, but the effect varied among species, suggesting that different habitat requirements may help drive variation in colonization rates. This article provides the first detailed evaluation of how a diverse community of birds has responded to one of the largest, ongoing reforestation projects in Hawai′i.     

鹤山丘陵退化生态系统植被恢复的土壤动物群落结构

对南亚热带恢复生态学研究基地-鹤山丘陵综合试验场20a人工植被林土壤动物群落进行了调查研究。研究样地包括草坡、松林、荷木混交林、马占相思林和豆科混交林。结果表明:在个体数量上,豆混林与马占林之间不存在显著差异,但与其它林分间差异明显(p<0.05);草坡土壤动物个体数明显处于最低水平;在类群的丰富度上,豆混林显著(p<0.05)高于所有其它林分,但无论是林分之间抑或季节之间,其变化的幅度都明显比个体数小;根据DG指数,各人工林可明显分为豆混林()、马占林()和荷混林()、针叶林()、草坡()3个层次。季节的差异很明显,湿季各项指标都低于干季。土壤表层各项指标的绝对值都与F2、F3层有极显著的差别(p<0.01),而F2、F3层之间却非常接近。长角跳虫科、鳞跳虫科、蚁科、康虫八科、蟹蛛科、巨蟹蛛科、球蛛科、鞘翅幼虫和半翅幼虫与群落总体特征(DG指数)的相关性都达到显著水准(p<0.05)。DG指数在反映不同人工林土壤动物群落特征上具有很好的稳定性。     

Allelopathy: a tool for weed management in forest restoration

Forest restoration uses active management to re-establish natural forest habitat after disturbance. However, competition from early successional species, often aggressively invasive exotic plant species, can inhibit tree establishment and forest regeneration. Ideally, restoration ecologists can plant native tree species that not only establish and grow rapidly, but also suppress exotic competitors. Allelopathy may be a key mechanism by which some native trees could reduce the abundance and impact of exotic species. Allelopathy is a recognized tool for weed management in agriculture and agroforestry, but few studies have considered how allelopathic interactions may aid restoration. Here we introduce the “Homeland Security” hypothesis, which posits that some naïve exotic species may be particularly sensitive to allelochemicals produced by native species, providing a tool to reduce the growth and impacts of invasive exotic species on reforestation. This article explores how exploiting allelopathy in native species could improve restoration success and the re-establishment of natural successional dynamics. We review the evidence for allelopathy in agroforestry systems, and consider its relevance for reforestation. We then illustrate the potential for this approach with a case study of tropical forest restoration in Panama. C₄ grasses heavily invade deforested areas in the Panama Canal watershed, especially Saccharum spontaneum L. We measured the effect of leaf litter from 17 potential restoration tree species on the growth of invasive C₄ grasses. We found that leaf litter from legume trees had a greater inhibitory effect on performance of S. spontaneum than did litter from non-legume trees. However, allelopathic effects varied greatly among species within tree functional groups. Further evaluation of intra- and inter-specific interactions will help to improve our selection of restoration species.     

Response of wood-inhabiting fungal community to fragmentation in a beech forest landscape

Fragmentation of natural habitats has become one of the main causes of the loss of biodiversity. To assess the effects of forest fragmentation on wood-inhabiting fungal community in a beech-dominated landscape, 15 differently shaped beech forest fragments were examined in northern Spain. This work covers all the wood-inhabiting macromycetes, including Basidiomycota and Ascomycota. A modelling approach was used to examine the predictability of the fungal community in a fragmented beech forest landscape. In the beech forest patches, a large proportion of edge, low tree densities and low levels of variety of woody debris caused a decrease of wood-inhabiting fungal richness. The fungal community composition proved complex to model due to its specific traits: it is made up of many species, most of which are rare, and each fungal group responds differently to environmental variables. Nevertheless, the dead wood availability and the exposure to light significantly affected the fungal community composition.